1. FIELD OF THE INVENTION
The present invention relates generally to automotive drum brakes, and in particular is concerned with a protective sleeve for an adjuster screw assembly of a drum brake.
2 . Description of the Related Art
Adjuster screw assemblies for drum brakes are well-known. Typically, an adjuster screw assembly includes a pivot nut threaded onto a screw. A star wheel is attached to or formed on the screw opposite the pivot nut. An actuating mechanism rotates the star wheel and screw as brake shoe linings wear from use. As the screw is rotated, a greater length of threads is exposed to corrosive elements such as water, ice, mud, etc.
Exposure to these elements can result in components of an adjuster screw becoming corroded, particularly at the point where the screw enters the nut, and thus inoperative. Traditionally, grease has been used to protect the screw and prevent corrosion. Over time, however, grease on the screw can wash away or chemically break down due to high temperatures. Corrosion can occur as moisture combines with lining dust and dirt that collect on the threads.
It is desirable to protect the adjuster screw assembly from corrosion. Furthermore, it is desirable to provide an economical solution to possible corrosion which can be incorporated into conventional adjuster screw assemblies.